The objective of the proposed research is to develop a technique for the preparation of isolated intact and living retinal neurons for electrophysiological and pharmacological study. This will be accomplished through enzymatic and mechanical dissociation of the adult goldfish retina. Isolated neurons will be immobilized and morphologically identified. Intracellular recordings will be obtained from them under visual observation with Nomarski interference contrast microscopy. The chemosensitivity of isolated neurons to retinal neurotransmitter candidates will be tested with technique of microiontophoresis. Ionic and conductance mechanisms underlying responses of isolated cells to transmitter candidates will be investigated and will be compared with respective properties of the same cell types in the intact retina. The proposed research is expected to contribute to our understanding of the microphysiology of synaptic function in the distal retina.